My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

At the age of eleven, I began Euclid, with my brother as my tutor. This was one of the great events of my life, as dazzling as first love. I had not imagined there was anything so delicious in the world. From that moment until I was thirty-eight, mathematics was my chief interest and my chief source of happiness.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

When two great powers disagree about anything - it doesn't matter what - they must find a way to settle it somehow by arbitration or by negotiation, not by war or threat of war.

In all the creative work that I have done, what has come first is a problem, a puzzle involving discomfort.

The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt. Even those of the intelligent who believe that they have a nostrum are too individualistic to combine with other intelligent men from whom they differ on minor points.

Moral progress has consisted in the main of protest against cruel customs, and of attempts to enlarge human sympathy.